ADSORPTION OF DYES AND PROTEINS TO MONOLAYERS

Abstract

The reflection of light at the air/water interface is modified by formation of a monolayer. In the presence of dye molecules at the interface the reflection spectrum coincides with the absorption spectrum of the dye monolayer. Using the reflection technique the adsorption of ionic dyes from the aqueous subphase to mixed monolayers including head groups of opposite charge have been investigated. Electrostatic binding of the dye is enhanced at constant charge density if the charge distribution matches that of the adsorbate. Binding of cytochrome c to phospholipid monolayers is dominated by electrostatic interactions. The porphin chromophore of the adsorbed protein is oriented parallel to the monolayer plane.